Yes, that is typical and the recommended choice especially when there are several systems on that router.

Two ways to get a static IP address for a system in your lan:
1) manually perform the TCP settings on the system
2) use address reservation feature of the router to always assign the same IP address to a specific system.

The first can be a chore and easily create problems, so I recommend using the latter.

Choice (2) needs the MAC (or physical address) of the target system. Get your system connected using the WiFi. Now get a command prompt (Start->Run->Cmd)
and enter ipconfig /all.
The line shown as physical address: . . . xx:aa:bb:cc:dd:ee is what you want to copy down.

In the router configuration, find the LAN side settings
and you can force xx:aa:bb:cc:dd:ee => ip 111.222.333.444

the important part is to make sure the last digits in the IP (eg 444 above) is beyond
the highest address assigned by the DHCP range.